• The Journal of Fisheries Business Administration
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• v.46 no.1
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• pp.63-74
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• 2015

Due to red tide and abnormal currents that take place every year, the damage of inland fish farms that takes sea water is increasing frequently. Also, the households of inland fish farm due to the increase in the cost of fuel and electricity are struggling many hardships economically. In relation to underground seawater for it's farm analyzed economic effect based on the actual conditions for 1,700 inland fish farms, from this I have deduced policy implications for direction this project to be pursued from now on. The saving rate of costs of the fuel and electricity through the development of an underground seawater were approximately analyzed to decline about 3.4~9.7%, if utilizing only about 5% of the undeveloped farms, it was estimated effect of about 61 billion won, if 10%, it was estimated effect of about 122 billion won. Consideration in selecting the developer of underground seawater will be selected an character of farm method. It is expected this study will be helpful for business analysis related government in the fisheries.

• Journal of environmental and Sanitary engineering
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• v.10 no.3
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• pp.56-66
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• 1995

To investigate environmental impacts of inland fish- farms on the water quality of a stream, environmental parameters including physical, chemical and biological factorswere estimated at trount- farm in 1994. Influences( F-1) were polluted as passing through fish tank( F-2) and settle pond( F-3), so organic and inorganic nutrient concentrations became very high in effluents( F-4). BOD$_{5}$, Chl. a, Nitrite and heterotrophic bacterial numbers in the junction site(5-2) of F-4 and S-1( upstream) were highest among the stream sites. BOD$_{5}$ was proved to a good parameter of organic pollution, and nitrite of Inorganic nutrients in the fishery and it's affected stream, The high concentration of BOD$_{5}$ and Chl. a in S-2 were decreased in downstream(5-3, 5-4). It seems that this results are due to dilution or sedimentation effect. This supposition requires further testing about the sediment of stream. The results of this paper demonstrate that fish farming can deteriorate water quality of a stream by changing environmental factors.

• Korean Journal of Ichthyology
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• v.32 no.4
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• pp.232-238
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• 2020

The objective of the present study was to investigate fish farm and growth performances of Chinese muddy loach (Misgurnus mizolepis) under indoor and outdoor aquaculture conditions for the domestic loach aquaculture industry. The investigation was conducted from August 2017 to October 2019 at one indoor farm (D-site) and two outdoor farms (P1-site and P2-site). Results showed that WG (weight gain), DWG (daily weight gain), and SWG (specific weight gain) based on growth measurements were 175.27±36.2%, 7.98±3.3%, and 0.94±0.2% at D-site, 320±34%, 4.07±0.6%, and 0.55±0.1% at P1-site, and 295.9±53%, 4.15±0.5%, and 0.62±0.1% at P2-site, respectively. WG was higher in outdoor farms (P1-site and P2-site), while DWG and SWG were higher in the indoor farm (D-site). Such differences of the present study might be due to differences in growth, water quality, plant and sale frequency depending on aquaculture types. In particular, outdoor farms takes more than a year to have sales whereas indoor farms can have sales three times in a year.

• Journal of Navigation and Port Research
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• v.34 no.1
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• pp.77-82
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• 2010

These days our coasts have been damaged by the polluted water resulting from the construction of industry on the shore, increasing population and urbanization. The destruction of ecosystem has induced many problems to aquaculture such that it raises the production cost of aquatic products for eating. For solving these problems aquafarm has been moving to the land. This paper intends to describe the automatic feeding system for the inland fish farm. An existent automatic feeding system has problems such that feed quantity is not accurate and feed itself is broken by feed motor. But a proposed system in this paper is more accurate than the existent system in view of feed quantity by using the combination of valve and load-sell. Resultantly, the system can safely transfer feed to inland nursery tank. Through several experiments using a real system, the effectiveness of the proposed system is verified under all conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.910-916
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• 2022

The purpose of this study is to evaluate the effect of underwater non-thermal dielectric barrier discharge plasma (DBD plasma) on the sterilization of three types of pathogenic bacteria that cause diseases in freshwater fish and the reduction of a tetracycline antibiotics. This experiment was conducted in the DBD plasma generator, and the voltages used to generate plasma were 11.6 kV and 23.1 kV. The measurement intervals were 0, 1, 5, 10 and 15 min. As a result of DBD plasma treatment, Aeromonas hydrophila, Edwardsiella tarda and Pseudomonas fluorescens were removed 93-99% after 5 min at 23.1 kV, and the tetracycline antibiotics were reduced 70-95% after 15 min at 23.1 kV. In this study, as a result of treating the effluent with DBD plasma at a fish farm where the medicinal bath was conducted with oxytetracycline-HCl (OTC-HCl) products, OTC-HCl decreased by 62% after 10 min at 23.1 kV.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.1
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• pp.47-53
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• 2018

The presence of pathogens in wild fish is a potential threat to the fish being raised nearby fish farm. Surveillance of these pathogens in the wild is, thus, highly important to keep fish in the farm safe from serious communicable diseases. Fish and crustacean were sampled 4 times at Soyang Lake in 2016. Pathogens for five reportable communicable diseases including KHVD (koi herpesvirus disease), SVC (spring viraemia of carp), EUS (epizootic ulcerative syndrome) and WSD (white spot disease), and parasites were investigated. In Soyang Lake, pale chub Zacco platypus was the most abundant. Forty seven pale chub, 8 Korea piscivorous chub Opsarichthys uncirostris, 3 oily shiner Sarcocheilichthys variegatus wakiyae and 2 crucian carp Cyprinus carassius were investigated for detection of target diseases of fish. Seventeen Caridina denticulata denticulata, 12 Oriental river prawn Macrobrachium nipponense and 1 Chinese mitten crab Eriocheir sinensis were used for detection of WSD. As the result, reportable communicable diseases were not detected in all the freshwater animals. Dactylogyrus was detected in Korea piscivorous chub. Copepoda was also detected in pale chub and Korea piscivorous chub. Metacercaria was detected in the pale chub sampled in September and October. Those were not metacercaria of liver fluke Clonorchis sinensis.

• Journal of fish pathology
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• v.13 no.1
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• pp.15-20
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• 2000

Infection rates with white spot baculovirus(WSBV) in wild-caught shrimp spawners appeared to be 52% in Penaeus chinensis and 20% in Penaeus japonicus when diagnosed by polymerase chain reaction (PCR). Infection rates of WSBV from inhabitant organisms in shrimp farm showed 37% in Upogebia major and 29% in Calliamassa japonica. The viruses maintained their survivorship in seawater at $4^{\circ}C$, but lost it at $25^{\circ}C$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.59-67
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• 2022

This study assessed the levels of water qualities and microbials contamination of inland olive flounder farms in Jeju in the summers from 2015 to 2017. Three farms (A-C) located in a concentrated area using mixing coastal seawater and underground seawater and one farm (D) located in an independent area using only coastal seawater were selected. Total ammonia nitrogen (TAN) reached a maximum of 0.898 ± 1.024 mg/L as N in the coastal seawater of A-C, which was close to the limit of the water quality management goal of the fish farm. TAN in the influent from A-C was up to three times higher than that of D, so that the discharged water did not spread to a wide range area along the coast and continued to affect the influent. TAN of the effluent in A-C increased by 2.7-4.6 times compared to the influent, resulting in serious self-pollution in the flounder farm. Heterotrophic marine bacteria in the influent of A-C was about 600 times higher than D, and the discharge of A-C was increased by about 30 times compared to the influent.

• Journal of Internet of Things and Convergence
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• v.2 no.3
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• pp.31-35
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• 2016

IoT technologies have been rapidly developed in recent years, and applied to many industries. In the field of fisheries, the water quality management system have been developed, helping in improving productivity and working environment. In this paper, we have designed the smart feeding system, interoperable with the water quality system, using LPWA network. LPWA network is an IoT network, which is appropriate to fish farms because of its wide area coverages and low power consumption. We expect this work to contribute to developing the aquaculture technology through the big data analysis with the accumulated data.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.604-608
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• 2009

This study was conducted to evaluate extruded pellet (EP) diet compared with a raw fish moist pellet (MP) diet for flounder, Paralichthys olivaceus on field feeding experiments in Jeju area. The experimental EP diet (juvenile, growing and adult) was prepared based on the former studies on nutrient requirements and feed ingredient of flounder. Fish were distributed randomly to each aquarium as a group of 102,300 fish (initial mean weight 97 g) in field experiment I and reared randomly to each aquarium as a group of 40,000 fish (initial mean weight 120 g) in field experiment II. In field feeding experiment I conducted in commercial flounder farm, survival, wt. gain (94-1,090 g), feed efficiency and condition factor of fish fed experimental EP were comparable to those of fish fed MP, but considerably higher protein efficiency ratio were observed in fish fed experimental EP. In field feeding experiment II, no significant difference was observed in final mean weight of fish fed the experimental EP (1,234 g) and MP (1,286 g), and any noticeable problem caused by feeding the experimental EP was not found during the whole period of feeding trial. Survival of fish fed the experimental EP was lower than that of MP, and there was no significant difference in feed efficiency between the fish fed experimental EP and MP. Therefore, these results strongly suggest that diet EP could be developed to replace MP diet for the marketable size (1.3 kg) of production for flounder without adverse effects on growth performance. In particular, abdominal dropsy and reduction of condition factor, which are frequently occurred in commercial EP feeding farms, were not observed in flounder fed experimental EP.